Hi,
Failed my SVA today on speedo - my greengauges one is faulty and sticking at 30mph. What's the best mountain bike one to fit as a backup if I don't get my new dial in time for my re-test?
Appologies for posting on here as I have a 2ltr Pinto, but you guys know your stuff when it comes to speedos!
Pat.....

I had the same problem . . . I bought a Sigma BC 1200 from Halfords. Don't buy the wireless ones or the Halfords own brands, no good.

I extended the cable by about 2m and put the sensor on the front upright.

SVA centres (most, possibly all ?) use a speedo calibration machine that relies on the car driving the wheels - put the sensor on the front and all they'll ask you to do is drive round the SVA site with the inspector as a passenger and he'll check that 20mph indicated "fells like about 20mph". (The Inspectors words, not mine)

Put it on the back of the car and they'll check the accuracy . . .

The BC1200 is a reasonably basic speedo but it's quite usefull in that it has settings for two different wheel sizes (so you can swap wheels and don't need to re-program it) and records driving time, gives you a clock and notes your max speed !

[Edited on 27/7/04 by bike_power]

ive got a photo of one of those whilst i was testing it on my pillar drill, it read steady up to 119mph, thats some push bike, never got as far as puttiing it car thats why i dint recomend it, but seems its ok on a car as well as a drill.........

Be careful Pat.
I've heard that mounting on the front wheels now requires independent calibration.
I mounted a C10 on rear wheels.
I calbrated at the the test. Simply alter the circumference setting you enter in. As the speedo reading must be higher than the actual (Or exactly the same)

Dont get Halfords own as fibre optic cable.

And dont forget to illuminate it. A white LED will do the trick

[Edited on 27/7/04 by Lightning]

As lightning says, a Cytec C10 running off the rear will do the job. I have a letter from the manufacturer in Germany stating that it is accurate to 135mph which apparently could be used for SVA if mounted to run off front wheels.

http://www.cobr.co.uk/acatalog/e_cobr_Online_Shop_VDO_CYTEC_C10_7962.html

Would this fit into the R1 speedo ?

Ok,
Got myself a cheap and cheerful cateye velo5 - upto 185mph so should just be ok (he he he).
Where's the best place to mount the magnet and sensor at the back. i've heard people mounting it on a drive shaft, but how do you calibrate it then????
Cheers,
Pat....

If it's on a drive shaft it still turns once to each turn of the wheel so the wheel circumference should do it. You could mount the magnet on the brake drum.

[Edited on 30/7/04 by Peteff]